Feature/generate

```
$ rails console
Loading development environment (Rails 4.0.4)
irb(main):001:0> first_user = User.first
  User Load (0.3ms)  SELECT "users".* FROM "users" ORDER BY "users"."id" ASC LIMIT 1
=> #<User id: 1, name: "test1", email: "test1@test.com", created_at: "2014-03-20 08:44:05", updated_at: "2014-03-20 08:44:05">
irb(main):002:0> first_user.microposts
  Micropost Load (3.5ms)  SELECT "microposts".* FROM "microposts" WHERE "microposts"."user_id" = ?  [["user_id", 1]]
=> #<ActiveRecord::Associations::CollectionProxy [#<Micropost id: 1, content: "テスト1", user_id: 1, created_at: "2014-03-20 08:43:23", updated_at: "2014-03-20 08:43:23">, #<Micropost id: 3, content: "テスト1-1", user_id: 1, created_at: "2014-03-20 08:43:47", updated_at: "2014-03-20 08:43:47">]>
```